Raspberry Pi 4B Case with cooling fan, power button, LED, external I/O connector and Pi Camera slot

Raspberry Pi 4B Case with cooling fan, power button, LED, external I/O connector and Pi Camera slot
 

This is a small case for the Raspberry Pi 4B. It provides lots of cooling and enough I/O to control my 3D Printer.

Edit 2022-12-20: Published a suitable holder for this case that attaches to the frame of the Prusa MK3S+ (and similar models).

Edit 2023-01-12: Thijs Triemstra pointed out that it's now possible to move I2C (GPIO 3 and GPIO 4) to different pins: https://raspberrypi.stackexchange.com/a/117019 

Design considerations

This remix is based on the Raspberry Pi 4B Case (30mm fan), with vertical stand, with heatsink, display, camera, pins option from Thingiverse user zenopeno. His version is a remix of the Parametric Raspberry Pi 4B Case (30mm fan) with vertical stand by scaryPug 
which is, in turn, based on John_Sinclair's design.

I like zenopeno's version since it has lots of vent holes and a perfect fit; the RPi 4B board is nicely clamped by the case. My design re-uses his variant with a slot for the Pi camera ribbon cable and modifies it as follows:

• added a "power" button
• added a 3 mm "status" LED 
• added a 3.5 mm audio jack to control an external relay
• removed the huge hole for the cooling fan 
• removed the mounting frame for the cooling fan (it did not fit my fan)

The open grid style of the case together with the lateral vent holes are sufficient to keep the board cool. The cooling fan is now simply glued in place with hot glue. 

To keep the look clean and avoid dangling wires in all directions, the switch and LED are located on the same side as the USB-C power port, and the 3.5 mm audio jack is squeezed in the small space above the Ethernet port.

Note: the ribbon cable in the photo has now been replaced by a much longer cable, but the camera is still the same.

Printing

• Print with flat side down
• Top and bottom layers 0 so that the infill becomes visible 
• Infill density around 30 
• Infill Pattern "Stars" (or whatever you like)

Other parameters are visible in the screenshots.

I printed this in two different colors of PLA - bottom in gray, top in white. This case is in use for more than a year now and I have not seen any problems of the material softening. 😎

Bells and whistles, uhm: connectors

The power button is used to start up and shut down the RPi, with the press of a button. 

• The button connects physical pin 5 (GPIO 3) to the GND next to it. 
• The startup functionality is enabled by default. 
• To enable shutdown with the same button, add dtoverlay=gpio-shutdown to /boot/config.txt
• Note: this does no longer work when I2C is enabled. / Update 2023-01-12: it's now possible to move I2C (GPIO 3 and GPIO 4) to different pins: https://raspberrypi.stackexchange.com/a/117019 

The green status LED lights up as long as the Pi is powered on. 

• LED goes to pin 15 and GND. 
• Don't forget the current limiting resistor.
• Edit /boot/config.txt and add gpio=15=op,dh (output, driving high)

The 3.5 mm audio jack is internally connected to GPIO 21 and GND. With the OctoPrint "GPIO" plugin, this I/O controls a 230 V relay, which can switch the printer power on and off.

Fan control is achieved by adding the following line in /boot/config.txt:

dtoverlay=gpio-fan,gpiopin=14,temp=60000

Now the fan will spin up briefly upon boot, then remain silent unless the chip temperature reaches 60°C.

Thanks to zenopeno and John Sinclair for their models 😃